Chub machines are well known in the packaging industry, and can be used for many flowable or extrudable materials. For example, various edible products such as ground meat, cheese, liver sausage, butter, ice cream and cookie dough have been packaged utilizing the chub machines. Inedible products have also been packaged utilizing the chub machines, including explosives.
In operation, a chub machine continuously unwinds and forms a tube from a roll of film, fills the tube with a flowable material, gathers or constricts at regular intervals short lengths of the filled tubing, applies a pair of closure clips to each gathered length of tubing, and severs the gathered or constricted material between the individual clips in a pair thereof. In one type of chub machine, two strands of wire from coils or reels are unwound and cut off at predetermined lengths from the ends of the wires so as to provide the clips, which are then suitably formed and constricted in pairs to each gathered length of tubing. In another type of chub machine, preformed clips are used.
The primary operating components or elements of a chub machine are: the tube-forming mechanism whereby a web of film is withdrawn from a supply roll, folded over around a hollow mandrel into a tube and heated or otherwise sealed; a product metering pump which injects flowable product through the mandrel out into the tube; a tube or film feed mechanism which continuously feeds the tube over and away from the mandrel; a voider which flattens or collapses short lengths of the filled tube at predetermined intervals; and a clipping head which applies a pair of spaced clips to the voided and gathered tube and severs the tube intermediate the clips. These operating components or subassemblies may be manually operated, or the chub machines may be provided with automatic control and monitoring systems, such as that set forth in U.S. Pat. No. 5,241,800 to Steinke et al., incorporated by reference herein in its entirety.
An example of a chub machine having automatic control is provided in FIG. 1. The chub machine, as indicated generally at 5, will be recognized by those familiar with chub machines as having a film arbor 6, a mandrel 7, a tube seam overlap heat sealer 8, a product delivery pump 9, a film drive 10, a voider 11, a clipping head assembly 12, a wire feed/cut-off assembly (not shown) carried by the clipping head, and a drive mechanism (not shown) housed in the base 13 of the machine. As is well known to those familiar with chub machines, conventionally, a web 14 of packaging film is continuously withdrawn from the arbor 6 when the machine 5 is in operation. The web 14 is led to a film folder 15 where the film is folded and its side edges overlapped thereby forming the web into a tube surrounding the mandrel 7. The sealer 8 acts to heat seal or otherwise bond the overlapped edges thereby completing the formation of a continuous tube. The film drive 10 engages the exterior of the tube and serves to continuously feed the tube downwardly. Below the film drive mechanism 10 the tube receives a metered quantity of flowable product through the mandrel 7. On passing through the voider 11 the voider rolls, at predetermined intervals, depending on the length of the packages being formed, momentarily swing inwardly together compressing the product-filled tube and thereby substantially voiding or expelling product from a short length of tube which has been flattened between the voider rolls. Each voided length of the tube is gathered in the clipping head 12 and a pair of vertically spaced clips applied to the gathered tube. The lower clip completes the formation of the upper end of one chub package while the upper clip forms the lower end of the next package. Immediately following the application of the clips a reciprocating knife severs the tube midway between the clips thereby allowing the completed chub package P to exit the machine.
Referring further to FIG. 1, the automatic control and monitoring system comprises: a pump drive servo 20 operatively connected to the product delivery pump 9; a film drive servo 21 is operatively connected to the film drive 10; and a clamp drive servo 22 is operatively connected to the clipping head 12. A machine controller 23 in the form of a microprocessor or computer of known commercial type is a key component of the control and monitoring system.
Inputs to the controller 23 are connected in signal receiving relationship to the servos 20, 21 and 22 and also to the heat sealer 8 and voider 11 as indicated. Three outputs of the controller 23 are connected to three servomotor controls 24, 25 and 26 of known commercial type which are in turn connected in signal delivering relationship to the servos 20, 21 and 22, respectively, as diagrammatically indicated.
Another output of the microprocessor controller 23 is operatively connected to a display 27, which is housed in a custom designed operator interface membrane panel 28. The monitor 27 serves as a computer display which enables the operator to effectively manage high levels of production from the chub machine 5 using easy to read symbolic keys on the membrane panel, multiple language screen displays and memory storage registers for various product operating presets. There may also be included a full range of screen displayed alarms and diagnostics to ensure minimum down time. Thus, the various components of the chub machine, such as the product delivery pump, tube or film feed, film heat sealer, voider and the clamping mechanism of the vertically reciprocating clipping head may all be automatically controlled by means of servo actuators operatively connected to a microprocessor.
It is often desirable to insert a loop or tie under one of the clips of a chub package to support or hang the filled chub package on a rack or hook for further processing, such as smoking, cooking or the like, or for display. It is also desirable to automate the operation of positioning a loop or tie in the pathway of the metal clip prior to application of the clip. Various methods and apparatuses have been designed for accomplishing loop attachment. One such mechanism is disclosed in U.S. Pat. No. 5,755,022, which is incorporated by reference herein in its entirety. Despite these attempts, there remains a need for an improved mechanism for feeding loops to chub packages in a chub machine, including a loop attachment accessory that may be added to an existing chub machine without interfering with the operation of the chub machine.